You can search LibrarySearch for print and ebooks. After searching, use the Availability filters on the right to limit your search by format (and more).
You can also find useful books in mathematics and related disciplines in the library stacks within the following Library of Congress call number ranges and subjects:
An online reference library comprised of reference books including encyclopedias, dictionaries, thesauri and books of quotations, etc.
Streaming video spanning a wide range of subject areas. A comprehensive, multidisciplinary video subscription.
Public Performance Rights: Films include limited public performance rights, which includes permission for classroom showings, as well as public screenings, as long as no admission is being charged.
You can look for books in other libraries.
Another great Google product! Find books online - some with limited content, some entirely online.